Silicon is now in very limited use as an industrial material, and is used mainly as a silicon nitride (Si3N4) compound. For information on silicon nitride industrial materials, reference may be made to “2005 Fine Ceramics Industry Trend Search,” Japan Fine Ceramics, published in November, 2005. However, silicon in the form of a silicon alloy has not yet been used as an industrial material in applications where its structural strength is relatively important.
Since silicon nitride is formed by a covalent bond of silicon and nitrogen in the uniform ratio of 3:4, impurities, especially metallic elements such as oxygen and iron, should not be included at all.
Material costs, and the cost of synthesis and processing of silicon nitride are extremely high, and consequently, the silicon nitride is yet to become an efficient form in which to utilize silicon as an industrial material.